1. Field of the Invention
This invention relates to dentifrice compositions containing finely divided synthetic amorphous silica polishing agents. More particularly, it relates to either translucent or opaque dental creams.
2. DESCRIPTION OF THE PRIOR ART
Commercially available silica xerogels are currently used as the polishing agent in translucent dental creams. These creams are translucent because the 1.46 refractive index of the solid phase, which is essentially a silica xerogel, matches that of the liquid phase, which is essentially a humectant and water.
In preparing them, the humectant concentration in the liquid phase is adjusted so the refractive index of this phase matches that of the solid phase. These silica xerogels require high concentrations of humectant, for example 70% sorbitol or 90% glycerin. Additionally, they are difficult to prepare because of the gelatinous nature of the crude gel.
Dental creams containing readily prepared silica polishing agents that do not require high humectant concentrations to give translucent creams would be an advancement in the art.